Apparatus for withdrawing masking material from bulbs



Oct. 29, 1957 T. F. MAY ETAL APPARATUS FOR WITHDRAWING MAsKING MATERIAL FROM BULBS Filed April 1o. 195s 3 Sheets-Shea?I 1 A Win A TA N .Il N R wy O O O TTI Mp A Z Y 7 T .B Zr C 7 xr@ 411. .fu [l WN ze 7 \f J V f VNIMW/ l. Q f, HMI" /l/. d 7 o Oct. 29, 1957 T. F. MAY ErAL APPARATUS FOR WITHDRAWING MASKING MATERIAL FROM BULBS Filed April l0. 1.953

3 Sheets-Sheet 2 Wlan/M Oct. 29, 1957 T. F. MAY ETAL APPARATUS FOR WITHDRAWING MASKING MATERIAL FROM BULBS Filed April 10, 1953 3 Sheets-Sheet 5 INVENTORS 7.' F'. Mymfd E. EPEELY. 6 ATTORNEY United States Patent G APPARATUS FOR WITHDRAWING MASKNG MATERAL FROM BULBS Theodore F. May, Verona, and Charles R. Edgerly, Bloomfield, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 10, 1953, Serial No. 348,044 4 Claims. (Cl. 302-1'7) This invention relates to coating the interior surfaces of translucent vitreous envelopes with specular material, preferably metal such as silver or aluminum.

The principal object of our invention, generally considered, is to manufacture bulbs for heat, spot, ilood and sun lamps, as well as for other devices in which radiant energy is to be reflected therefrom in a certain direction, by applying a specular coating of a metal, particularly silver, as an example, over a portion only of such bulbs, the remainder being kept clear to allow the radiant er1- ergy to freely emerge therefrom.

Another object of our invention is to coat bulbs for radiant energy devices with reflecting material, while portions thereof are covered with a suitable masking material, to leave a translucent or transparent window in each bulb to thereby allow for the transmission of radiant energy in a desired direction.

A further object of our invention is to provide a machine for automatically adjusting the masking material in the bulb, evacuating, flashing specular material on the unmasked portion of the bulb, removing the coated bulb from the machine, and transferring the masking material to another bulb to be coated.

An additional object of our invention is to provide improved means for withdrawing the granular masking material from each bulb and transferring it to another bulb to be coated.

Other objects and advantages of the invention will become apparent as the description proceeds.

In the drawings:

Fig. l is an elevational view, with a part broken away, of a lamp of a type manufactured in accordance with our invention.

Fig. 2 is a vertical sectional view of a bulb used to make a lamp of a type such as that illustrated in Fig. l, and showing specular material on the interior surface thereof, with the exception of the lower or bowl portion which has been kept from the application of such material during the course of manufacture.

Fig. 3 is a diagrammatic plan view of an automatic machine for coating bulbs in accordance with our invention.

Fig. 4 is a plan of apparatus for withdrawing granular masking material from a bulb which has been coated and transferring it to a bulb to be coated.

Fig. 5 is an elevational view, with parts in vertical section, of the apparatus shown in Fig. 4.

Fig. 6 is a transverse sectional view on the line VI-VI of Fig. 5, in the direction of the arrows and to a larger scale.

Fig. 7 is a fragmentary transverse sectional View on the line Vil-VII of Fig. 5, in the direction of the arows and to the scale of Fig. 6.

The Green Patent No. 2,569,852 dated October 2, 1951, discloses and claims apparatus which is very satisfactory for the manufacture of reflecting bulbs for devices, such as infrared lamps and sun lamps, provided the specular material applied to such bulbs is a relatively durable met- 2,811,394 Patented oct. 29, 1957 lCC al such as aluminum. However, when it is desired t0 substitute a softer metal, such as silver, for such aluminum there is danger of the granular masking material, which may be glass beads, scratching the coating and creating a poor product, if the unloading mechanism disclosed in said patent is employed.

In other words, the reversing of the bulbs after coating, from a position in which the necks extend upwardly to one in which they extend downwardly, results in the granular masking material rubbing the specular coating, thereby running the risk of damage thereto unless said coating is relatively durable. In accordance with our invention, we propose to substitute a suction withdrawal of such masking material from the bulbs after coating, for that by reversal in position, thereby preventing the masking material from abrasively engaging the coating material in order to avoid damage thereto.

Referring to the drawing in detail, like parts being designated by like reference characters, there is shown in Fig. l a lamp 11 comprising an envelope or bulb 12 closed by a stern 13 carrying an energy-translating filament device 14, and having a base 15 which may be screw-threaded. The base-adjacent portion of the bulb is shown covered on the inside thereof with a reflecting coating 16,

which coating may be of a suitable specular material,`

preferably silver because of its high reflectivity, although alternatively it may be of aluminum or other desired metal, flashed or vaporized thereon in a man-ner fully ex plained in the Green patent above referred to. The bowl portion 17 of the bulb opposite the base may be either clear or frosted, as desired.

In practicing our process, we first take an open neck glass bulb or envelope 12, and invert it to the position represented in Fig. 2. A measured quantity of granular masking material 18, preferably line glass granules, but which may be alundum powder or other heavy, fine, preferably non-metallic powder of granular material, is then poured therein as from a receptacle or other bulb. The granular material 18 is desirably, although not necessarily, what is called Barium Crown Glass Beads, preferably .014 in diameter, and between the limits of .014H and .017, as manufactured by Potter Bros. of Long Island. This granular material may be evenly distributed in the bowl portion of the bulb in any desired manner, preferably by twirling as disclosed in the Green patent referred to.

After being so distributed, the bulb is placed in a coating machine which may be generally of the type described and claimed in said Green patent, previously referred to. Such a machine is diagrammatically illustrated in Fig. 3 and the operator, so designated in said figure, may load such bulbs thereon at position 23 or 124. At positions l through "7 such bulbs are given a preliminary exhaust and at positions 8 through l5 they may get a final exhaust. At positions 16 through 18j the metal is flashed to apply a specular coating to the unmasked portions of the bulbs.

The only difference between the flashing operation in the present instance and that of the patent referred to, is that silver is preferably employed rather than aluminum, and the flashing filament is desirably formed of flattened tantalum wire rather than tungsten wire, as such wire has been found to ywork better with silver than tungsten wire.

After ashing has been completed, the bulb is removed at position 22 and placed on a support 19, desirably formed of Bakelite of similar material which, in turn, rests on -a platform of table 21. The Bakelite support has an aperture 22 therein through which the central portion of the bowl of the bulb projects, Ias shown most clearly in Fig. 6. Beneath this aperture are mirrors 23 and 24, so that the operator can tell when the masking material has been entirely withdrawn from the bulb. The neck of the bulb is supported Ibetween a pair of springs 25, held on a bracket 26, in turn carried by a supporting wall or upright member 27.

We provide ya vacuum suction tube 28 for withdraw-V ing the masking material 18 from the interior of each bulb 12, after coating on the machine represented in Fig. 3. This tube is mounted for vertical reciprocation in corresponding apertures in brackets 2.9 and 31 secured to the wall 27 as by means of bolts 32. The uppermost bracket 29 carries a pad 32 of rubber or other resilient material which acts as a stop for a cam member 33,

which may be generally inverted frusto-conical in shape and secured to the suction tube 28, as` Vby means of a set screw 34. .The tube 2S is held in desired position by an encircling dog 78 which Ibites it when canted, as shown in full lines, and releases it when the carrying handle 77, biased to biting position by spring 79, is raised to dotted position. A collar 81 specially formed with end air-directing pockets 80, is secured in adjusted position on said tube by set screw S2.

The upper end of the tube 28 is connected to the upper end of a tube by means of a rubber or other flexible air-tight tube 36. The details of this exible tube need not be fully disclosed, as they are not part of the invention, except that the tube is not only air tight and flexible, but is suciently conductive so that it does not become appreciably charged, with static electricity during operation, so thatthe pellets of granular material stick thereto. In order to avoid such sticking, the ends of the tube 36 are grounded, as indicated at 37 and 38.

The tube 35, in turn, connects with a hopper 39 for receiving the masking material after it is withdrawn from a bulb 12. This hopper is connected to a vacuum. pump, or other source of vacuum, by means of a suitable pipe 41, the connection to said source being preferably controlled by a normally-closed solenoid valve 42 operated from a source :of power, not shown. The electric current to said valve 42 is, in turn, controlled by a switch 43, closed and opened, respectively, by downward and upward reciprocation of the cam member 33 on the suction tube 28.

In order to avoid 'granular material being sucked into the vacuum line during operation, the pipe 35 discharging into the hopper 39 is provided with a Haring terminal portion44, in turn surrounded by a restricting skirt portion 45 connected to the inner surface of the hopper 39. Above the skirt portion 45 is another similar but shorter skirt portion 46, encircling a bae member 47 of generally conical shape. The latter is held in place by supporting legs 48, the ends `of which are flanged as indicated yat 49 and respectively secured to the cone 47 and the interior surface of the hopper 39.

The upper end of the hopper 39 is partially closed by an annular header member 51 secured thereto as by screws 50. There is secured to said member 51, as by means of bolts carrying thumb nuts 52, a frusto-conical connecting tube 53. Tightness of connection is insured by gasket means 54. Disposed within the tube 53, and the base or lower flange portion of which is held between the base of said tube 53 and the member 51, is a generally conical metal screen 55 of line mesh, to prevent undesired withdrawal of particles of masking material from the hopper into the vacuum line.

The upper end of the tube 53 is, in turn, secured to the vacuum line 41, as by means of clamps 56. The lower end of the hopper 39 is generally hollow, frustoconical, and terminates in a discharge pipe 57, normally closed by a tapered plug valve 58. This valve 58 is connected to a collar 59, slidably mounted on the discharge pipe 57, as by means of connecting rods 61, whereby said plug valve is drawn to the normally-closed dotted position shown in Fig. 7 by means of biasing coil spring 62. The rods 61 are guided in a terminal block 63, which supports the spring 62 and is secured to the lower end of the discharge pipe 57, as by means of set screw 64,

Disposed beneath the discharge pipe 57 is a receiving funnel 65, terminating in a discharge pipe 66. The funnel 65 carries the valve 58 by receiving the end portions of the stands or stems 83, which extend from the valve 58, and to which the lower ends of the rods 61 connect. Over the pipe 66 telescopes a larger discharge pipe terminal member 67. In order to prevent complete separation of the pipes 66 and 67, the former carries a collar or 4lower end flange 68, whereas the latter carries a header 69 on its upper end, in which is set plate member 71. This member 71 encircles the pipe 66 and engages the lower end flange 68 thereof, when in the extreme lower position illustrated in Fig. 7.

The header 69 carries trunnions 72 journaled in a frame 73 connected to the wall 27 by pivot member 74 extending through bracket 75. The frame is provided with a manually-operable handle 76. The handle, normally raised to extreme top position by spring acting on frame 73, when pulled down to lowermost position, as shown in full lines in Fig. 7, elects introductionV of the llerpipe 67 into an empty bulb 12, without engaging the bottom thereof. This bulb may be supported, as illustrated in Fig. 7, in a manner similar to the bulb in Fig. 6, except that no mirrors need be disposed therebeneath. When the handle 76 is in uppermost dottedline position, the filling tube 6'7 is withdrawn from the bulb, telescoping over the tube 66 until, in extreme upper position, it permits the valve member 58 to rise to the closed position represented in dotted lines.

Operation The apparatus illustrated in Figs. 3 to 7, incl., may be used Yas follows. A bulb after coating, and containing masking material 18 to be withdrawn therefrom, is by the :operator positioned beneath the suction tube 28, -as shown 4in Fig. 6. The masking material is Withdrawn from said bulb 12, by iirst lifting to dotted position the handle 77, which carries a tube-encircling dog 78, and thereby releases the tube 28, allowing it to drop down into the bulb 12, untilrit is stopped by engagement of its cam member 33 with the rubber cushion 32 on the shelf 29.

The cam member 33 on said tube finally closes the* switch 43, energizing the solenoid of and opening valve 42, thereby -introducing suction to draw the masking material 18 lupwardly and through the arcuate tube 36, to finally discharge it into the hopper 39 above an empty bulb 12, disposed as shown in Figures 5 and 7. By virtue of the specially formed collar 81, adjusted to position on the lower portion of the tube 28, and held by means of set screw S2, the currentsof air which pass through the neck Aof the bulb 12 and by said tube are particularly effective for carrying all of the masking material 18, from the bulb to be emptied, into the suction tube 28, from whence it is nally depositedin the hopper 39.

When the bulb 12 has been completely emptied, this being determined by the operator viewing the bottom thereof by the use of the mirrors 23 and 24, the operator then pulls down on the handle 76, first withdrawing the tube 67 to extended position from the tube 66, as shown in Fig. 7, and finally removing the valve 58 from the lower end of the tube 57, by means of the connection with the valve stems 83 which pass through a side of the funnel 65.

This means that the material in the hopper 39 then ows freely into the funnel 65 and through the tubes 66 and 67 into the bulb 12. When this has been accomplished, the bulb after twirling as disclosed in the Green patent previously referred to, so that the masking material is properly distributed, -is loaded on the machine, illustrated in Fig. 3 at position 23 or 24, and the cycle is repeated.

Although a preferred embodiment has been disclosed, it will be understood thatmodications may bemade within the spirit and scope of the invention.

lbeneath, a vacuum line, a norm-ally closed solenoid valve therein, a power circuit lthereto, a switch in said circuit, a hopper connectable to said line, downward movement of said suction tube into said bulb causing closing of said switch to effect openin-g of said valve, whereby movement of said suction tube controls the connection and disconnection of said line with respect to said hopper, a

, telescopic discharge conduit extending from said hopper,

a valve normally preventing said hopper from discharging its contents, means for supporting an empty bulb, open neck upward, `beneath said hopper, means connecting said suction tube to said hopper for the discharge of masking material thereinto, and a handle controlling the discharge from said hopper, in order to trst arrange for the ow of material into an empty bulb therebeneath rby causing extension of said telescopic discharge tube into said bulb and, thereafter, causing opening of said hopper valve to allow material to flow from said hopper into said bulb.

2. Mechanism for unloading Ibulbs which contain granular masking material after removing from a machine which has applied specular coatings to unmasked portions of their interior surfaces, comprising a suction tube mounted for vertical reciprocation, a dog-carrying handle associated with said suction tube for normally holding it in any desired position, and when moved upwardly releasing it to cause downward reciprocation into a bulb to be emptiedwhen disposed therebeneathpa vacuum line, a hopper connectable to said line, means actuated by movement of said suction tube for controlling the connection and disconnection of said line with respect to said hopper, a discharge member depending from said hopper, a valve normally closing said discharge member, spring means urging said valve to closed position, a funnel disposed beneath said discharge member, means connecting said funnel and valve so that when said funnel is lowered it opens said valve, a pipe depending from said funnel for carrying material therefrom, a second pipe telescoping over said first pipe, the lower end of said rst pipe carrying a shoulder, the upper end of said second pipe carrying a shoulder and at the lower limit of downward movement of said second pipe over said lirst pipe, engaging said iirst shoulder to stop further relative movement, prior to carrying said funnel down to effect opening of said valve .and discharge of material from said hopper into said funnel, means for supporting an empty bulb open neck upward beneath said funnel, means connecting said suction tube to said hopper, and a handle `pivotally mounted and connected to said second pipe to effect reciproc-ation thereof, in order to first move said tube into an empty bulb and, thereafter, pull down on said funnel to open said valve and effect discharge of material from said hopper to said bulb.

3. Mechanism for unloading-bulbs which contain granular masking material after removing from a machine which has applied specular coatings to unmasked portions of their interior surfaces, comprising a suction tube mounted for vertical reciprocation, ya dog-carrying handle associated with said suction tube for normally holding it in any desired position, and when moved upwardly releasing said suction tube to cause it to reciprocate downwardly into a bulb to be emptied when disposed therebeneath, a vacuum line, a hopper connectable to said line, means actuated by movement of said suction tube for controlling the connection and disconnection of said line with respect to said hopper, baliies in said hopper for preventing the withdrawal of masking material when suction is applied thereto, a telescopic discharge conduit extending from said hopper, a valve normally preventing said hopper from discharging its contents, means for supporting an empty bulb open neck upward beneath said hopper, exible means connecting said suction tube to said hopper for the discharge of masking material thereinto, and a handle controlling the discharge from said hopper, in orderto first arrange for the ow of material into an empty bulb therebeneath by causing an extension of said telescopic discharge conduit into said bulb and, thereafter, causing opening of said hopper valve to allow material to-ow from said hopper into said bulb.

4. Mechanism for unloading bulbs which contain 'granular masking material after removing from a machine which has applied specular coatings to unmasked portions of their interior surfaces, comprising a suction tube mounted for vertical reciprocation, means for holding therebeneath a bulb to be emptied, a dog-carrying handle associated with said suction tube for normally holding said tube in any desi-red position and, when moved upwardly, releasing said suction tube ,to cause it to reciprocate downwardly into said bulb, a cam device carried by said tube, a vacuum line, a solenoid valve therein, a power circuit thereto, a switch in said circuit, said cam device causing closing of said switch to efectopening of said valve when the suction tube is lowered into said bulb, a hopper connected through said valve to said vacuum line, a discharge member depending from said hopper, a valve normally closing said discharge member, spring means urging said valve to closed position, a funnel disposed beneath said discharge member, means connecting said funnel and valve so .that when said funnel is lowered it opens said valve, a pipe depending from said funnel for carrying material therefrom, a second pipe telescoping over said lirst pipe, the lower end of said tirst pipe carrying a shoulder, the upper end of said second pipe carrying a shoulder which, at the lower limit of downward movement of said second pipe over said lirst pipe, engages said first shoulder to stop further relative movement, prior toV carrying said funnel down to eiect opening of said valve and discharge of hopperenclosed material into said funnel, means for supporting an empty bulb open neck upward beneath Said funnel, means connecting said suction tube to said hopper, and a handle pivotally mounted and connected to said second pipe to ettect reciprocation thereof, in order to irst move said second pipe into an empty bulb and thereafter pull down on said funnel to open said valve and effect discharge of material from said hopper to said bulb.

References'Cited in the tile of this patent UNITED STATES PATENTS 219,019 Renard et al Aug. 26, 1879 228,206 Luckenbach June 1, 1880 692,106 Bedarrides Jan. 28, 1902 1,495,487 Johnson May 27, 1924 2,247,432 Birdseye et al. July 1, 1941 2,349,444 McGowan May 23, 1944 2,447,337 Hoch Aug. 17, 1948 2,569,852 Green Oct. 2, 1951 2,658,657 Fechheimer Nov. 10, 1953 

